2,4-D, Cotton, and Sprayer Contamination
The three leading causes of 2,4-D injury are: volatilization (or vapor
drift), spray drift, and sprayer contamination. The potential for
injury from each of these causes can be greatly reduced by adhering to
best management practices as described in the following paragraphs.
The final way in which cotton
injury can occur is from minute residues of 2,4-D (banvel or phenoxy
herbicides) in a sprayer. It is recommended highly that any sprayer
previously used to apply 2,4-D not be used in cotton. If such a sprayer
must be used, it should be washed thoroughly before spraying cotton.
Special attention should be given to sprayers used to apply
emulsifiable concentrates because these products seem to be
particularly effective at pulling 2,4-D residues out of a sprayer.
procedure is recommended for washing out sprayers that have been used
to apply 2,4-D. Keep in mind that this procedure may not totally remove
2,4-D residues. Dispose of rinsates in an approved manner. Rinsates
resulting from this product may be disposed of on-site or at an
approved waste disposal facility.
- Remove nozzles, nozzle
strainers, and in-line strainers. Using a soft brush, wash the nozzles
and strainers with soapy water. Be sure to remove any visible deposits.
- Before replacing nozzles
and strainers, fill sprayer tank (at least 1/4 full) with water and add
a strong detergent such as 4 pounds of trisodium phosphate per 50
gallons of water or a commercial spray tank cleaner. Agitate for 15
minutes and then flush about one-fourth of the water-detergent mixture
through the lines. Replace nozzles and strainers and flush remainder of
water detergent mixture through the nozzles.
- Spray diesel fuel on the
inside surfaces of the tank. Start the sprayer to fill the lines, and
let the diesel fuel sit in the lines for several hours, preferably
overnight. Then spray out the diesel fuel. (Note: this step is
suggested only if the sprayer has previously been used to apply an
ester formulation of 2,4-D.)
- Fill the tank (at least
1/4 full) with water and add household ammonia at the rate of 1 quart
per 25 gallons of water. Agitate for 15 minutes, spray a few gallons of
the mixture through the nozzles, and let the remainder sit in the tank
and lines for several hours, preferably overnight. Then spray out the
remainder of the ammonia-water mixture.
- Fill the tank (at least 1/4 full) with water and detergent. Agitate for several minutes and spray it out.
- Fill the tank (at least 1/4 full) with fresh water and spray it all through the nozzles.
Be careful not to introduce 2,4-D from other sources, such as using a 2,4-D measuring device to measure cotton pesticides.
If you have any
questions regarding the use of products containing 2,4-D ester contact
your local retailer or Cooperative Extension Service representative for
adapted from: "Mr. Cotton Doesn't Like Miss Ester: A Practical Guide to
Significantly Reducing 2,4-D Injury to Cotton" produced by the 2,4-D
Ester Stewardship Program.
ALWAYS READ AND FOLLOW ALL LABEL PRECAUTIONS AND DIRECTIONS.